Even beforethe settlementof the Cistercian monks, the place wasinhabited byBenedictine monkswho hadbuilt amonastery withthe titleSt. Stephenthe First Martyr,where healso livedGregory IVdell'827firstyear of hiselection to thepapacy.Later, probably around the yearone thousand, the monastery wastherestructuringand expansion, of which stillremainwell preserved, the three sidesof theRomanesquecloister.